Method for producing beryllium alloys



Patented Jan. 14, 1941 Herbert Gruber, Werner Hessenbruch, and WilhelmRohn, Hanan, G

ermany, asslg'nors to Heraeus-Vacuumschmelzej A. 'G., Hanan-onv 1the-Main, Germany No Drawing. Application March 13, 1939, Serial No.261,649. In Germany March 25, 1938 8 Claims (01. 7545:)

This invention relates to a method for producing beryllium alloys, moreparticularly alloys of beryllium with heavy metals, especially withcopper. 1

It is known that beryllium alloys of this type can be produced byreducing beryllium oxide with carbon in the presence of a molten bath ofthe metal with which the beryllium is to be alloyed. For example, thebath may be composed of 10 copper, or a metal of the iron group (iron,nickel,

cobalt) ora metal of/the chromium group (chromium, molybdenum, tungsten,uranium), or a molten bath containing a mixture or an alloy of severalof these metals may be used. 1 One of the most important berylliumheavymetal alloys is the copper-beryllium type. and by following the abovegeneral procedure, using copper for the molten bath, an alloy may beproduced having aberyllium content anywhere up to about 3.54%. However,difliculties are. encountered when attempts are made to operate in amanner to produce a beryllium-copper, alloy having a higher berylliumcontent. For economic reasonsit is desirable to be able to produce ahigher-percentage beryllium master alloy, which could then be employedfor the production of beryllium-copper alloys having lower berylliumcontent, for instance\ irom about 1.5 to about 2.5%, by diluting withmore copper. I It has been known that beryllium-copper alloys of thetype having a percentage of beryllium up to about 3.5 to 4%, may beproduced by the thermic reduction method briefly described above, 1 thealloys being practically carbon-free, especially it after the reductionis ended the excess carbon is caused to rise by twirling or spinning themetal bath, in the general manner in which kish graphite is removed.Certain of the difllculties which are encountered when attempting toproduce beryllium-copper alloys having a beryllium percentage aboveabout 4%, are not encountered when operating with a molten bath of. oneor more of the metals nickel, cobalt and iron. With these metals 4; ofthe iron group, especially with nickel or cobalt,

an alloy containing from about 12-15% beryllium, balance nickel orcobalt, may eilectively be produced. The operating costs involved inthis procedureare substantially the same as those for the production ofa 24% beryllium-copper alloy, and

' therefore theproductlon costs of a given weight of beryllium contentin the beryllium-nickel alloys are less than in the case or theberylliumcopper alloys. However. it has been found that in producing aberyllium-nickel alloy, substantial quantities of carbon remaindissolved, this diiliculty being especially noticeable .when thereaction takes place in air. While the quantity of dissolved carbon canbe reduced by remelting the, alloy in the 5 presence of furtherberyllium oxide, and prefer- -ably under reduced pressure, thisprocedure is disadvantageous since a considerable loss of berylliumresults due to the fact that beryllium and beryllium carbide evaporate.In consel0 quence, removing the dissolved carbon in this way results ina drop in the beryllium content from the initial quantity of about12-15% down to about 5-7 With the foregoing difficultiesin mind, the 15present invention contemplates production of a beryllium-heavy metalalloy, especially a beryllium-copper alloy, by first reducing berylliumoxide with carbon in the presence of a molten bath of nickel, cobalt'oriron, to produce a beryl- 0 lium-nickel alloycontaining, for example,from 12-15% beryllium. In producing a berylliumcopper alloy thisberyllium-nickel alloy is then diluted with a substantial quantity ofcopper, which has the eflect of precipitating the dissolved 25 carbon. I

The amount of dilution necessary in most instances to accomplish theprecipitation of the carbon is from about 35-40%, although for'mostpurposes it is found desirable that the copper 30 should heavilypredominate in the final alloy, the copper being preferably in excess ofThe reduction of the beryllium oxide in .the

.presence of the molten bath may take place in air, or in the vacuumchamber, or in the hydrogen 35 atmosphere. If desired, lime, or calciumcarbide or other similarfiuxes may be used.

It should also be noted that it is not necessary to employ. pureberyllium oxide in carrying out the reaction. The beryllium oxide may bepres- 40 cut in the form of ore, ,in which event other oxides may bepresent. The beryllium oxide may be mixed with the carbon in the form ofgraphite or in the form of a carbide, especially beryllium carbide, andthis mixture then introduced intcr 45 the molten bath.

The amount of copper added to dilute the alloy first produced (forinstance the beryllium-nickel alloy) may be such as to produce aberyllium content from'about .3-10%. In most instances, how- 50 ever, itis preferable that the dilution should be sufllcient to result in acopper content well over 75%. a 7

As an example, a beryllium-nickel alloy may first be produced containing15% beryllium, and

this alloy then diluted with about seven times its weight of copper,thereby resulting in an alloy containing about 87.5% copper, about 2%beryllium, and the balance nickel. An alloy having the beryllium andnickel percentages of about the order just indicated, is found to havephysical properties essentially equivalent to a comparable alloyofberyllium and copper alone, especially with respectto high mechanicalhardness, elasticity, and wear and fatigue resistance. The alloycontaining .nmliel" (inaddition to the beryllium and copper) ,can beheat treated by precipitation hardening in much the same way as pureberyllium-copper alloys, 1. e. by quenching from temperatures betweenabout 600 and 80 0 C. and

then annealing at temperatures between about 250 and 400 C. i

As another example of the application of the invention, reference ismade. to the use of a.

molten cobalt bath, for the purpose of producing first aberyllium-cobalt alloy and then diluting this alloy with copper, theoperation being car- -ried out, for instance, to result in a berylliumcontent of about .4% and a cobalt content of about 2.6%, copperrepresenting the balance. Alloys of this general class are outstandingfor certain purposes because of possessing particularly high hardness,coupled with good electrical conductivity, making them especiallysuitablefor welding electrodes, switches, contact parts and the like.

It will be apparent also that various mixtures of nickel, cobalt andiron may be used, depending upon .the purposes for which the-alloy isbeing prepared. Similarly, the extent of dilution with copper will varyin accordance with the properties desired. 4

In instances where it is desirable to have silicon present in the alloyin addition to the beryllium, the invention contemplates addition ofsilicon either to the molten bath initially or simultaneously with theberyllium oxide. Since silicon reduces the solubility of carbon inmetals of the iron group, when using a molten nickel, cobalt or ironbath, very little if any carbon remains. The addition of silicon is alsoadvantageous because it reduces the melting point of the master alloysproduced in view of which such master alloys will dissolve more rapidlyand easily in a moltenbath of copper which may be used for dilution.

As an example. of the use of silicon, reference may be made to theproduction ofan alloy suitable ior welding electrodes, in which asilicon content in the neighborhood'of 5% is desirable, Thus, whenproducing an alloy for welding electrodes having in the neighborhoodof.5% beryland thereby nickel, or cobalt, or iron base alloys may beobtained, which are very low in carbon.

In all examples according to the invention, it is possible to produce aninitial alloy having high beryllium content which initial alloy maysubsequently be fdiluted, the dissolved carbon being reduced eitheratthe time of reduction (by the addition of silicon) or at the time ofdilution (by dilution with copper).

We claim:

1. The method of producing a substantially carbon-free alloy containingberyllium'and copper and in which the copper heavily predominatesoverthe other ingredients, which method includes bringing into reactionberyllium oxide andcarbon in the presence of a molten bath of a metalchosen from the group consisting of nickel, cobalt and iron to producean alloy of beryllium and said metal and in which carbon is alsopresent, thereafter diluting the alloy with copper in an amountproviding a copper content of at least 35%, to precipitate the carbonremaining in the alloy; from said reaction.

2; The method of producing a substantially carbon-free alloy containingberyllium and copper and in which the copper heavily predominates overthe other ingredients, which method includes bringing into reactionberyllium oxide and carbon in the presence of a molten bath of a metalchosen from thegroup consisting of nickel, cobalt and iron-to produce analloy of beryllium and said metal in which the beryllium constitutesfrom about 12-15%, and thereafter diluting the alloy with copper inanamount between that lower limit which will provide an alloy containingat least about 35% copper and that upper limit which will provide analloy containing at least about .3% beryllium.

,3. The method of producing a substantially carbon-free alloy containingberyllium and copper and in which the copper heavily predomi- -withcopper in anamount such that the copper constitutes at least 75% of thealloy.

4. The method of producing a substantially carbon-free alloy containingberyllium and copper and in which the copper heavily predominates overthe other ingredients, which method includes bringing into reactionberyllium oxide and carbon in the presence of a molten bath of a metalchosen from the group consisting of nickel, cobait and iron to producean alloy of beryllium and said metal in which the beryllium constitutesin the neighborhood of 12-15% of the alloy, and thereafter diluting thealloy with copper in an amount suflicient to reduce the berylliumcontent to a percentage of the order of 2% 5. The method of producing asubstantially carbon-free alloy containing beryllium and copper and inwhich the copper heavily predominates over the-other ingredients, whichmethod includes" bringing into reaction beryllium oxide and carbon inthe presence of a molten bath of cobalt to produce a beryllium-cobaltalloy in which the cobalt heavily predominates and in which asubstantial amount of carbon is also present, and thereafter dilutingthe alloy with copper to precipitate the carbon and to reducethe-beryllium content to a percentage of the orderof.4%. 6. The-methodof producing a substantially carbon-free alloy containing beryllium andcopper and in which the copper heavily predominates over the otheringredientsfwhich method bringing into reaction beryiiium and carbon inthe presence of a molten bath of a metal chosen from the groupconsisting of ni'ckel, cobalt and iron and also in the presence ofsilicon to produce an ,alloy of beryllium, silicon and the metal of saidgrpup in which the beryllium constitutes from about 12-15%, andthereafter diluting the alloy with copper in an amount between thatlower limit which will provide an alloy containing at least about 35%copper and :the presence of a molten bath of a metal chosen 4 from thegroup consisting of nickel, cobalt and iron and also in the presence ofa quantity of silicon approximately equal to the quantity of berylliumto be reduced in the metal of said group to produce an alloy ofberyllium, silicon and the metal of said group in which the berylliumconstitutes from about 12-15%, and thereafter diluting the alloy withcopper in an amount between that lower limit which will provide an alloycon .taining at least. about 35% copper and that upper limit which willprovide an alloy containing at least about .3% beryllium.

8. The method of producing a substantially carbon-free alloy ofberyllium with a heavy metal in which the heavy metal content heavilypredominates over the other ingredients, which method includes bringinginto reaction beryllium oxide and carbon in the presence of a moltenbath of a metal chosen from the group consistingof nickel, cobalt andiron and also in the presence of silicon to produce an alloy ofberyllium, silicon and the metal 0! said group very low in carbon inwhich the beryllium constitutes from about 12-15%, and thereafterdiluting the alloy with a heavy metal in an amount between that lowerlimit which will provide an alloy containing at least about 35% or saidheavy metal and that upper limit which will provide an alloy containingat least about 3% beryllium.

HERBERT GRUBER. WERNER. HESSENBRUCH.

